Does Antibacterial Mouthwash Reduce Nitric Oxide From Beetroot?

Written by Lize Bührmann, founder of Pharmatropia.

Strong antibacterial mouthwash can reduce the oral conversion of nitrate from beetroot and leafy vegetables into nitrite, an early step in one pathway that produces nitric oxide. Small human studies suggest this effect can be measurable, but they do not prove that every mouthwash cancels every benefit of beetroot, nor that people should abandon necessary dental treatment.

The useful answer is nuanced: oral bacteria are part of nitrate metabolism, yet oral hygiene and professional dental advice remain important.

How does beetroot become nitric oxide?

Beetroot, rocket, spinach and other vegetables contain nitrate. After absorption, some nitrate circulates into saliva. Bacteria on the tongue reduce nitrate to nitrite. Once swallowed, nitrite can be converted further into nitric oxide and related compounds, particularly in low-oxygen or acidic conditions.

Nitric oxide is a signalling molecule involved in blood-vessel tone and other physiological processes. This nitrate–nitrite–nitric oxide route is different from the amino-acid pathway involving L-arginine and L-citrulline. Our comparison of beetroot versus L-citrulline explains that distinction.

What does the mouthwash research show?

In a small randomised crossover trial involving 15 adults being treated for hypertension, three days of twice-daily antibacterial mouthwash reduced oral nitrate-to-nitrite conversion. Compared with water, systolic blood pressure rose by about 2.3 mmHg. The study, published in 2015, supports the biological importance of oral bacteria in nitrate metabolism.

You can read the study abstract in PubMed. Its limitations matter: the group was small, the intervention was short, and one antiseptic formulation cannot represent every mouthwash, dose or pattern of use.

Other research has explored similar effects, but the evidence is not a licence to diagnose blood-pressure changes from mouthwash at home. Blood pressure varies for many reasons, and a single reading is not enough to establish cause.

Does mouthwash “block” beetroot supplements?

“Block” is too absolute. A broad-spectrum antibacterial rinse may suppress some nitrate-reducing bacteria and lower salivary nitrite production for a period. The size and duration of the effect can vary with the product, its active ingredients, timing, oral microbiome, diet and individual physiology.

Beetroot products also differ in nitrate content. A red powder or juice is not automatically nitrate-rich, and a label that lists beetroot without quantifying nitrate does not tell you the effective amount. Our overview of nitric-oxide support explains why the pathway and the product specification both matter.

Should I stop using antibacterial mouthwash?

Not without discussing why you use it. A dentist may recommend a particular rinse for gum disease, after a procedure or for another clinical reason. Untreated dental disease carries real risks. If your rinse was prescribed or recommended for a defined period, follow that plan unless your dental professional changes it.

If you use a strong antiseptic rinse routinely without a clinical reason, ask a dentist whether it is necessary and whether a gentler oral-care plan could meet your needs. The aim is not to preserve nitric oxide at the expense of oral health; it is to avoid unnecessary disruption while maintaining effective dental care.

Does timing the rinse away from beetroot help?

It is plausible that separating a nitrate-rich drink from an antibacterial rinse may reduce immediate overlap, but research has not established one universally reliable waiting period. Product activity and dosing differ. Avoid turning an unproven timing rule into a guarantee.

For most people, the stronger foundations are a vegetable-rich diet, regular brushing with fluoride toothpaste, interdental cleaning, dental check-ups, movement, sleep and appropriate medical management.

What about L-citrulline?

L-citrulline is converted to L-arginine and can feed nitric-oxide synthase pathways. It does not depend on tongue bacteria in the same way that dietary nitrate does. This means the mouthwash question is more directly relevant to beetroot and nitrate products than to L-citrulline, although overall cardiovascular safety still matters.

If you use blood-pressure medication, nitrates for chest pain, phosphodiesterase-5 medicines or multiple circulation products, read our guide to nitric-oxide supplements and blood-pressure medicine and speak to your clinician.

A practical approach

• Do not stop a prescribed dental product for supplement reasons.
• Ask what active ingredient your mouthwash contains and why you need it.
• Choose beetroot products by transparent nitrate information, not colour alone.
• Do not use mouthwash manipulation as a substitute for medical blood-pressure care.
• Measure blood pressure with a validated device if your clinician recommends monitoring.

Frequently asked questions

Does ordinary toothpaste reduce beetroot-derived nitric oxide?

The clearest evidence concerns antibacterial rinses designed to suppress oral bacteria. Toothpaste formulations vary, and routine brushing is essential. Do not avoid brushing in an attempt to improve supplement effects.

Are alcohol-free mouthwashes harmless to the nitrate pathway?

Not necessarily. “Alcohol-free” does not mean “non-antibacterial”. Check the active ingredients and ask a dental professional how the product is intended to be used.

Can tongue scraping affect nitrate conversion?

The tongue hosts nitrate-reducing bacteria, so intensive scraping could plausibly influence the ecosystem, but there is not enough evidence to recommend changing sensible tongue hygiene for this reason.

Is beetroot a treatment for high blood pressure?

No supplement should replace prescribed treatment. Beetroot nitrate has been studied for vascular effects, but results and products vary. People with hypertension should make changes with clinical guidance.

Educational note: This article is general information. It does not replace dental or medical advice, and it should not be used to change prescribed mouthwash or blood-pressure treatment.